1. Field of the Invention
The invention is directed to an optical module and an optical apparatus and more particularly, to a light source module and a projection apparatus.
2. Description of Related Art
Nowadays, projection apparatuses based on a solid-state light source, such as a light-emitting diode (LED) or a laser diode gradually play an important role in the market. A laser diode has luminance efficiency approximately higher than 20%, and thus, in order to breakthrough the limitation to the LED light source, a pure color light source for a projector, which is produced by a laser light source exciting phosphor, is gradually developed. Moreover, a laser projection apparatus may not only allow the laser light source to emit light by exciting the phosphor but also use the laser as a direct light source of the projector. Besides, the laser projection apparatuses have an advantage of adjusting the number of light sources based on brightness requirements to meet various demands on the different brightness rank of projector. Therefore, a projector structure using the laser light source as a light source module has a great potential for replacing the conventional type using the high pressure mercury lamp as a light source and accordingly, become the light source used in a new generation mainstream projector.
However, the laser light source is monochromatic, in other words, its light radiation has a narrower band. Thus, the light emitted by the laser light source is a monochromatic light in the color coordinates approaching the outer boundary of a horseshoe map of the CIE1931 space. Also, the current laser light source has limited selectable bands which result in limited selection of the pure colors and a challenge to meet usage demands of colors if a laser light source is to be adopted as a direct light source in a projector illumination system for achieving light mixing.
U.S. patent publication No. 20100245776 discloses a projector illumination system. U.S. patent publication No. 20050057145 discloses a white light emission means.